It is known to propel a marine vehicle utilizing a propeller assembly mounted on a rotatable drive shaft. The propeller assembly includes a plurality of propeller blades extending radially from a central hub. A motor rotates the drive shaft that, in turn, rotates the propeller blades propelling the marine vehicle through the water. Typically, the propeller assembly is constructed as a unit wherein the propeller blades and the central hub are mounted or removed from the drive shaft in unison. Alternatively, in order to reduce the time and costs associated with replacing the propeller blades, it has been contemplated to provide a propeller assembly for a marine engine wherein the propeller blades project from a propeller housing that is removable from a central hub.
By way of example, Chen, U.S. Pat. No. 5,967,751 discloses a marine propeller assembly that includes a central hub secured to the propeller shaft and having three or more axially extending keys on the outer surface thereof. A propeller housing includes an inner surface having three or more pairs of lobes for forming keyways that receive the keys of the central hub. A retainer disc is threaded on a propeller shaft and includes a plurality of angularly spaced ears for engaging with the lobes on the inner surface on the propeller housing in order to prevent the propeller housing from being disengaged from the central hub.
While the advantages of a removable propeller housing are readily apparent, it can be appreciated that it is often highly desirable to retain the propeller assembly on the propeller shaft in such a manner as to prevent any unnecessary movement of the propeller assembly that may reduce the overall efficiency of the drive system of the marine vehicle. However, during such circumstances when the propeller blades engage a fixed object in the water such as a rock or the like, it is highly desirable to prevent the abrupt stoppage of the drive shaft of the marine vehicle in order to prevent damage to the drive system. In addition, it may be necessary to disengage the drive shaft of the marine vehicle from the propeller housing in order to prevent damage to the drive system.
Therefore, it is a primary object and feature of the present invention to provide a hub assembly for a propeller which permits limited continued rotation of the spindle and propeller shaft before disengaging the propeller shaft from the central hub and propeller assembly.
It is a further object and feature of the present invention to provide a propeller assembly that may be simply and easily mounted on and removed from the drive shaft of a marine vehicle.
It is a still further object and feature of the present invention to provide a hub assembly for a propeller which is simple and inexpensive to manufacture.
In accordance with the present invention, a propeller assembly is provided for mounting on a rotatable propeller shaft of a watercraft. A housing structure extends along a longitudinal axis and has an inner surface defining passageway therethrough. The inner surface includes a first portion being a first radial distance from the longitudinal axis and a second portion being a second radial distance from the longitudinal axis. A spindle is receivable in the passageway of the housing. The spindle has an inner surface defining a passageway for receiving the propeller shaft therethrough and an outer surface. A longitudinally extending key extends along the outer surface of the spindle. The key includes a radially outer surface being a third radial distance from the longitudinal axis. The third radial distance is greater than the first radial distance and less than the second radial distance.
A bushing is molded over the outer surface of the spindle. The bushing includes an outer surface engageable with an inner surface of the housing structure. The bushing is formed from a resilient material and has a generally square-shaped cross section and rounded corners. The key fragments from the outer surface of the spindle in response to a predetermined force thereon. The inner surface of the spindle includes a plurality of longitudinally extending splines.
The inner surface of the housing structure has a generally square-shaped cross section. The inner surface of the housing structure is defined by first and second spaced sidewalls. The first and second sidewalls are generally parallel to each other. The inner surface also includes third and fourth spaced sidewalls. The third and fourth sidewalls are generally parallel to each other and are generally perpendicular to the first and second spaced sidewalls. The inner surface of the housing structure is further defined by a first rounded corner interconnecting the first and third sidewalls; a second rounded corner interconnecting the third and second sidewalls; a third rounded corner interconnecting the second and fourth sidewalls; and a fourth rounded corner interconnecting the fourth and first sidewalls.
In accordance with a further aspect of the present invention, a propeller assembly is provided for mounting on a rotatable propeller shaft of a watercraft. The propeller assembly includes a housing structure extending along a longitudinal axis. The housing structure includes an outer surface and an inner surface defining a cavity having a polygonal-shaped cross-section defined by at least one corner and at least one sidewall. A bushing assembly is receivable in the cavity of the housing structure. The bushing assembly includes a spindle and a bushing. The spindle has an inner surface defining a passageway for receiving the propeller shaft therethrough and an outer surface having a longitudinally extending key extending therealong. The key extends radially from the outer surface of the spindle toward a first corner of the at least one corner of the inner surface of the housing structure. The bushing is molded over the spindle. The bushing has an outer surface engageable with the inner surface of the housing structure.
The bushing is formed from a resilient material. The inner surface of the spindle includes a plurality of longitudinally extending splines. The outer surface of the housing structure has a plurality of circumferentially spaced blades projecting therefrom. The inner surface of the housing structure has a generally square-shaped cross section. The at least one sidewall of the inner surface of the housing structure includes first, second, third and fourth sidewalls. The first and second sidewalls are generally parallel to each other. The third and fourth sidewalls are generally parallel to each other and are generally perpendicular to the first and second spaced sidewalls. The at least one corner of the inner surface of the housing structure includes a second corner interconnecting the third and second sidewalls; a third corner interconnecting the second and fourth sidewalls; and a fourth corner interconnecting the fourth and first sidewalls.
In accordance with a still further aspect of the present invention, a propeller assembly is provided for mounting on a rotatable propeller shaft of a watercraft. The propeller assembly includes a housing structure extending along a longitudinal axis. The housing structure includes an outer surface and an inner surface defining a cavity. The inner surface is defined by first, second, third and fourth sidewalls. The first and second sidewalls are generally parallel to each other. The third and fourth sidewalls are generally parallel to each other and are generally perpendicular to the first and second spaced sidewalls. A first rounded corner interconnects the first and third sidewalls. A second rounded corner interconnects the third and second sidewalls. A third rounded corner interconnects the second and fourth sidewalls. A fourth rounded corner interconnects the fourth and first sidewalls. The propeller assembly also includes a bushing assembly. The bushing assembly includes a spindle and a bushing. The spindle has an inner surface defining a passageway for receiving the propeller shaft therethrough and an outer surface having a plurality of circumferentially spaced, longitudinally extending keys extending therealong. Each key of the spindle is directed toward a corresponding corner of the inner surface of the housing structure. The bushing is molded over the spindle. The bushing has an outer surface engageable with the inner surface of the housing structure.
The bushing is formed from a resilient material and the inner surface of the spindle includes a plurality of longitudinally extending splines.